To LSD or not

jcraigau · #1 (**permalink**) 05-02-2010, 05:53 AM

I'm just starting to put all the suspension on my new kit and the existing open 3.05 jag diff is in good nick so I was going to clean it up and use it to get through rego.

I've had a quote of $2600 to "swap" out to a 3.54 LSD. Not that money is that tight but it would buy me a lot of getting ready parts.

I know the LSD is the right way to go in the long run, how hard is it going to be to drop the new gears in later?

One day it will need to come back off the road for paint and that's when I was going to swap gears.

Thanks in advance,
JC

Zedn · #2 (**permalink**) 05-02-2010, 06:16 AM

You should be able to get an XJS diff for under $1000. Just keep an eye on ebay.

I am in the same boat. I am planning to register with the single spinner and see how it goes for traction. I had a bad experience with an LSD in the wet on my first car so am a bit scared of them.

You can simply buy an XJS diff and it will swap straight over with the XJ6.

andyl · #3 (**permalink**) 05-02-2010, 04:27 PM

Quote:

Originally Posted by Zedn

You should be able to get an XJS diff for under $1000. Just keep an eye on ebay.

I am in the same boat. I am planning to register with the single spinner and see how it goes for traction. I had a bad experience with an LSD in the wet on my first car so am a bit scared of them.

You can simply buy an XJS diff and it will swap straight over with the XJ6.

Hi Zedn,

I'm in the same boat too, are you saying all XJS diffs are LSD ? They do come up on ebay a bit but as a general rule their owners have no idea if they are LSD or not and what ratios and although its not hard to determine either they seem reluctant to have a go and do so. If all XJS's had LSD then that simplifies things a lot.

-Andy

Aussie Mike · #4 (**permalink**) 05-02-2010, 05:44 PM

Tenrocca · #5 (**permalink**) 05-02-2010, 06:19 PM

I only have a non LSD in mine, and I think with my lack of driving ability it is a good think. I feel that I would have had a lot more loses without that one wheel keeping some traction at the last nats (only time Ive been on the track)

Gav · #6 (**permalink**) 05-02-2010, 06:33 PM

An admission of incompetance Andy?

I have an LSD in mine and would have to say an open centre would probably be a bit more forgiving, mine is near on impossible to keep in a straight line when hanging a wheelie.
This could be due to a number of things like tyre pressure, lack of skill ect..

For the money you are taking about I would go an open centre and install an LSD at a later time if you feel the need.

Tenrocca · #7 (**permalink**) 05-02-2010, 07:40 PM

Quote:

Originally Posted by Gav

An admission of incompetance Andy?

No Gavin - just an attempt to make those even slower then me feel really bad.

Gav · #8 (**permalink**) 05-02-2010, 07:50 PM

Gavin?
Jeez haven't been called that since highschool.
Must be a teacher thing.

jcraigau · #9 (**permalink**) 05-03-2010, 12:47 AM

I've had LSD's for the last 15yrs so I know the pitfalls in the wet! The latest has the TC button, which just gets in the way...

I'm going to go ahead with the open diff for rego and "see how we go" after it's on the road.

boxhead · #10 (**permalink**) 05-03-2010, 12:55 AM

If I was in your boat JC I would stick to original plan, get it registered and use it, see if you like it and then change if needed.

Non LSD will be more forgiving for everyday use.

Zedn · #11 (**permalink**) 05-03-2010, 02:00 AM

Quote:

Hi Zedn,

I'm in the same boat too, are you saying all XJS diffs are LSD ? They do come up on ebay a bit but as a general rule their owners have no idea if they are LSD or not and what ratios and although its not hard to determine either they seem reluctant to have a go and do so. If all XJS's had LSD then that simplifies things a lot.

-Andy

Hi Andy,

It is my understanding that the XJS and XJ12 all have LSD's. But that is only what i was told by a Jag wrecker. The tag on the housing bolt is the best way. Most ebayers are happy to tell you what the tag says.

Liam

andyl · #12 (**permalink**) 05-03-2010, 03:11 AM

Quote:

Originally Posted by Zedn

Hi Andy,

It is my understanding that the XJS and XJ12 all have LSD's. But that is only what i was told by a Jag wrecker. The tag on the housing bolt is the best way. Most ebayers are happy to tell you what the tag says.

Liam

Thanks Liam, I was going off my open centre tag which while it explained the ratio gave little other information having just 2 numbers 49 & 13 on it. I took this as teeth on crownwheel & pinion giving 3.7692:1 (ie 3.77s which feels about right on the road too). I don't know what it will say on the tag in the case of an LSD, hopefully something obvious. This all assumes it has the tag still too. Good info though that more likely than not an XJS or XJ12 regardless of still needing to confirm it.

andyl · #13 (**permalink**) 05-03-2010, 03:22 AM

Hi JC,

I agree with Boxhead, what you have is free info, try it and see. It was the same case with me and one of the most important things is to see if the ratio is right for you and to give you a base to do calcs from. In my case I find the 3.77 a bit too low for the top loader so will probably go up a peg to the 3.54s but would not have known this unless getting rego with the 3.77s and trying them out. I suspect with your T56 (going off your bio) you'll be looking for lower than the 3.05s and possibly lower than the 3.54s too, I have a 3.82:1 gears in the 9" in my WB ute with a T56 and its a good match for me with such a tall overdrive so the free info gained by driving it around for a while might tell you that the 3.54s might still be too high and will save you money in the long run by getting it spot on when you swap.

-Andy

Zedn · #14 (**permalink**) 05-03-2010, 03:28 AM

Tag for LSD has some letters on it also i believe. If you search there is a post on here that talks about tags.

Liam

andyl · #15 (**permalink**) 05-03-2010, 03:39 AM

Quote:

Originally Posted by Zedn

Tag for LSD has some letters on it also i believe. If you search there is a post on here that talks about tags.

Liam

Thanks, you're right another thread has that it has either 'PL' on the tag or a second tag with 'BPL'. -Andy

jcraigau · #16 (**permalink**) 05-03-2010, 07:21 AM

Mine has two tags on it.

One has "3.058", the other has "CAC9040".
Not sure what it means as I've looked through all the manuals and I can't find it as a part number. Any ideas?

jcraigau · #17 (**permalink**) 05-10-2010, 05:03 AM

OK, now that I've decided to keep the existing diff (for now) I got into it with my cleaneruperer tools. Before I go all the way, I need another opinion from you guys.

Clear or black?

Thanks guys...

--JC

LoBelly · #18 (**permalink**) 05-10-2010, 05:45 AM

Black spray paint is the home mechanics savio(u)r...

LB

Rebel1 · #19 (**permalink**) 05-10-2010, 06:15 AM

1 coat Wattyl super etch
2 coats POR15 chassis black

It will then survive in the rotten Melbourne conditions.

eeek EDIT ... make that pleasant Perth conditions.

Rebel1 · #20 (**permalink**) 05-10-2010, 06:20 AM

This Aussie paint mob are said to be as good as POR15:
http://www.kbs-coatings.com.au/Rust-Sealer_c_7-1-0.html

Blacktop is their version of Chassis black

Not tried it myself tho.